Schikan updated investors and other stakeholders about Prosensa's plans for Duchenne muscular dystrophy (DMD) drug development at the Newsmakers in the Biotech Industry conference. The approximately 30-minute presentation, which includes audio and slides, was webcast live and is available for replay through the Events & Presentations section of Prosensa's website.
“We are of course disappointed about the results of the recent phase 3 trial of drisapersen,” said Jane Larkindale, MDA's vice president of research. “However, we are encouraged by the message of today’s presentation, which indicates that the company has every intention of continuing with its development of exon-skipping compounds for Duchenne dystrophy. Advances in exon skipping and all of the other therapeutic approaches to DMD will allow us to accelerate future DMD trials and other programs.”
Drisapersen results to undergo more analysis
Drisapersen, in development to treat boys with DMD who have mutations near exon (section) 51 of the dystrophin gene, did not show benefit on tests of walking distance or motor function in a 48-week, phase 3 trial that included 186 participants. A phase 2 trial had previously shown encouraging results with respect to walking distance and dystrophin protein production.
The design of the two trials, however, differed. Boys in the phase 3 trial for which results were announced this month may have been "more progressed" in their disease course than boys in the encouraging phase 2 trial, Schikan said, because they were not required to complete a "rising from the floor" test within a strict time limit.
"We are going to be evaluating the benfit-risk relationship of drisapersen," Schikan said. He noted that GSK had placed further dosing of drisapersen on hold for participants in current trials of the drug. In the meantime, he said, a review of all data related to drisapersen will be conducted and will likely be completed by the end of 2013.
Other Prosensa DMD studies will continue
Schikan said all other studies of Prosensa's DMD exon-skipping drugs will continue. "We will try to learn from the drisapersen experience," he said, adding that some adjustment in trial design may be made based on what is learned from the drisapersen data review.
Schikan noted that the exon-skipping compounds Prosensa is now developing are "going through a more rigorous process" than drisapersen did and that experimental compounds PRO045 (targeting dystrophin exon 45) and PRO053 (targeting dystrophin exon 53) appear to be more efficient than drisapersen at causing exon skipping in muscle cells.
The company plans to offer more details about drisapersen at the 18th International World Muscle Society Congress, to be held on the Asilomar Conference Grounds in California October 1-5, 2013.
"Our focus remains on Duchenne dystrophy," Schikan said.
For more information
For more about exon skipping and drugs for DMD based on this strategy, see: